Green fluorescent protein-like pigments optimize the internal light environment in symbiotic reef building corals

Pigments homologous to the Green Fluorescent Protein (GFP) have been proposed to fine-tune the internal light microclimate of corals, facilitating photoacclimation of photosynthetic coral symbionts (Symbiodiniaceae) to life in different reef habitats and environmental conditions. However, direct measurements of the in vivo light conditions inside the coral tissue supporting this conclusion are lacking. Here, we quantified the intra-tissue spectral light environment of corals expressing GFP-like proteins from widely different light regimes. We focus on (1) photoconvertible red fluorescent proteins (pcRFPs), thought to enhance photosynthesis in mesophotic habitats via wavelength conversion, and (2) chromoproteins (CPs), which provide photoprotection to the symbionts in shallow water via light absorption. Optical microsensor measurements indicated that both pigment groups strongly alter the coral tissue light environment. Estimates derived from light spectra measured in pcRFP-containing co...

与绿色荧光蛋白（Green Fluorescent Protein, GFP）同源的色素被认为可对珊瑚内部的光学微环境进行精细调控，助力珊瑚光合共生体（Symbiodiniaceae）适应不同礁栖生境与环境条件。然而，目前尚缺乏可支撑该结论的珊瑚组织内活体光照条件的直接测量数据。本研究对源自光照环境差异显著的类群、表达GFP同源蛋白的珊瑚，定量测定了其组织内的光谱光环境。本研究聚焦两类蛋白：（1）光转换红色荧光蛋白（photoconvertible red fluorescent proteins, pcRFPs），这类蛋白被认为可通过波长转换提升中光层生境中的光合效率；（2）发色蛋白（chromoproteins, CPs），这类蛋白可通过吸收光线为浅水区的共生体提供光保护。光学微传感器测量结果表明，这两类色素均可显著改变珊瑚组织内的光照环境。基于含pcRFPs的珊瑚中测得的光谱推导得到的估计值……